1. Field of the Invention
The present invention relates to a sheet-handling apparatus used for an image reading machine such as a copying machine and arranged to feed a document or a paper sheet on which an image is to be transferred, and more specifically to a sheet handling apparatus for two-side scanning and copying.
2. The Related Art
In an image reading machine or an image forming machine, such as a copying machine, a printer, an image reader, a facsimile or the like, the machine is provided with a sheet-handling apparatus for automatically feeding a sheet into the machine.
Generally, a sheet-handling apparatus comprising a sheet-fetching apparatus, a transporting assembly and sheet channels. The sheet-fetching apparatus fetches a sheet and sends the sheet into the sheet channels. The transporting assembly delivers the sheet to an image-processing area. After an image processed, the paper is sent out of the machine.
In order to effectively utilize the sheet, this image reading machine deals with the sheet on both sides of the sheet. A sheet-handling apparatus is provided for delivering a sheet into the machine for scanning or printing an image on one side of the sheet, then delivering the sheet into the machine again for scanning or printing an image on the other side of the sheet.
The sheet-handling apparatus comprises a sheet-fetching assembly, a transporting assembly and sheet channels. The sheet-fetching assembly fetches a sheet and sends the sheet to the sheet channels. The sheet channels comprise a first channel and a second channel. An image-processing area is arranged in the first channel. The second channel sends the one-side processed sheet to the image-processing area. The transporting assembly comprising a plurality of rolling wheels, a plurality of inert wheels, an exit-rolling wheel and an exit idle wheel. The exit rolling wheel and the exit idle wheel are located at a sheet exit. In general, a special motor drives the sheet-fetching assembly. When the motor running clockwise, the sheet-fetching assembly fetches a sheet. When the motor running counterclockwise, the sheet-fetching assembly rises. The exit-rolling wheel and the rolling wheels are driven by a sheet-feeding motor. The sheet-feeding motor runs reversely, so that the sheet is sent to the second channel.
While the sheet-handling apparatus works, the sheet-fetching assembly fetches the sheet into the first channel, then the paper is delivered to the image-processing area. After the sheet is sent to the exit-rolling wheel, the sheet is sent to the sheet exit. While the end of the sheet passes through the exit rolling wheel and the exit idle wheel, the exit-rolling wheel drives reversely, the sheet is sent to the second channel, and then the paper is delivered to the first channel. So that, the other side of the sheet is processed.
However, the structure of the conventional sheet-handling apparatus is very complex. Especially, the sheet-handling apparatus has many motors. For the motors, the sheet-handling apparatus has to arrange a lot of additional parts, such as speed-reducing gears, control means, linking elements, etc. Therefore, the structure of the sheet-handling apparatus is complex. Of course, it is not convenient for assembling, repairing and maintaining the sheet-handling apparatus.